hBitmap To Image Widget

[AppetiteTeam]

Hey!

Can someone tell me how to display a screenshot immediately in flutter.
It turned out without sticking a screenshot to the clipboard:

const int width = 300;
const int height = 300;

final int hScreen = GetDC(NULL);
final int hDC = CreateCompatibleDC(hScreen);
final int hBitmap = CreateCompatibleBitmap(hScreen, width, height);
final int old_obj = SelectObject(hDC, hBitmap);
final int bRet = BitBlt(hDC, 0, 0, width, height, hScreen, 0, 0, SRCCOPY);

OpenClipboard(NULL);
EmptyClipboard();
SetClipboardData(CF_BITMAP, hBitmap);
CloseClipboard();

But I can't display it immediately in the widget.
I played with this example for a long time, but I could not =(
https://github.com/timsneath/win32/blob/main/example/screenshot.dart

P.s. Yes, I need a 300x300 square

[AppetiteTeam]

Help

[jamiepiccolo]

I used the original screenshot example and replaced the section where it saves to a file with the below.

var b = BytesBuilder();
b.add(Pointer<Uint8>.fromAddress(bitmapFileHeader.address)
    .asTypedList(sizeOf<BITMAPFILEHEADER>()));
b.add(Pointer<Uint8>.fromAddress(bitmapInfoHeader.address)
    .asTypedList(sizeOf<BITMAPINFOHEADER>()));
b.add(lpBitmap.asTypedList(dwBmpSize));
return b.toBytes();

This gives you a bitmap as an array of bytes, which you can use with Image.memory(bytes) in flutter.

[chocolatedesue]

Any helpful info with region capture? I write some code but fail to work.

 static Uint8List captureRegion(int x, int y, int w, int h) {
    int hScreen = GetDC(NULL);
    int hDC = CreateCompatibleDC(hScreen);
    int hBitmap = CreateCompatibleBitmap(hScreen, w, h);

    try {
      int oldObj = SelectObject(hDC, hBitmap);

      BitBlt(hDC, 0, 0, w, h, hScreen, x, y, SRCCOPY);

      var bmp = calloc<BITMAP>();
      GetObject(hBitmap, sizeOf<BITMAP>(), bmp);

      final bitmapFileHeader = calloc<BITMAPFILEHEADER>();
      final bitmapInfoHeader = calloc<BITMAPINFOHEADER>()
        ..ref.biSize = sizeOf<BITMAPINFOHEADER>()
        ..ref.biWidth = bmp.ref.bmWidth
        ..ref.biHeight = bmp.ref.bmHeight
        ..ref.biPlanes = 1
        ..ref.biBitCount = 32
        ..ref.biCompression = BI_RGB;

      final dwBmpSize =
          ((bmp.ref.bmWidth * bitmapInfoHeader.ref.biBitCount + 31) /
                  32 *
                  4 *
                  bmp.ref.bmHeight)
              .toInt();

      var lpBitmap = calloc<Uint8>(dwBmpSize);
      GetDIBits(hDC, hBitmap, 0, bmp.ref.bmHeight, lpBitmap,
          bitmapInfoHeader.cast(), DIB_RGB_COLORS);
      var b = BytesBuilder();
      b.add(Pointer<Uint8>.fromAddress(bitmapFileHeader.address)
          .asTypedList(sizeOf<BITMAPFILEHEADER>()));
      b.add(Pointer<Uint8>.fromAddress(bitmapInfoHeader.address)
          .asTypedList(sizeOf<BITMAPINFOHEADER>()));
      b.add(lpBitmap.asTypedList(dwBmpSize));
      free(lpBitmap);
      free(bitmapInfoHeader);
      free(bitmapFileHeader);

      free(bmp);

      return b.toBytes();

      // GetClipboardData(CF_BITMAP);
    } finally {
      DeleteObject(hBitmap);
      DeleteDC(hDC);
      ReleaseDC(NULL, hScreen);

      CloseClipboard();
    }